Performance Characteristics of Lithium-Ion Technology Under Extreme Environmental Conditions
Marshall C. Smart, Ratnakumar V. Bugga, Keith B. Chin, Larry D. Whitcanack, Subbarao Surampudi · 1st International Energy Conversion Engineering Conference (IECEC) · 2003
Lithium-ion technology has been demonstrated to have high specific energy, high energy density, and relatively long life. In addition, lithium-ion technology is especially attractive since it has the potential to operate over a very wide temperature range, which is particular important for a number of applications. This potential derives from the fact that lithium-ion cells possess organic solvent-based electrolytes, in contrast to aqueous-based electrolytes, which can be tailored to provide high conductivity over a wide range of temperatures. Thus, in recent years, advances in electrolyte formulations have led to dramatic improvements in the capability of lithium-ion technology to operate at extreme temperatures, especially low temperatures. However, it still remains a challenge to demonstrate excellent low temperature capability throughout the life of a cell, especially after being subjected to high temperature cycling or exposure. In order to understand these performance limitations, a number of aerospace quality prototype cells, ranging in capacity from 1 to 45 AKr, have been tested over a wide range of temperatures (-70 to i-75OC). In addition, many cells have been tested under conditions of alternating high and low temperatures to determine the impact that variable temperature cycling has upon cell health and performance. To further elaborate upon possible performance degradation mechanisms present, the results of a number of experimental three-electrode cells will be presented. In addition to enabling us to monitor the individual electrode potentials during cycling, these cells have provided a test vehicle in which electrochemical characterization of electrode can be performed.